Field-effect storage tube with eas-discharge output

ABSTRACT

A field-effect storage cathode ray tube is provided with a gasdischarge panel arrangement for display output. A transparent conductive mesh is mounted within the panel adjacent the transparent front plate thereof, and an array of conductive pins extend through the panel backplate from within the panel to the other surface of the backplate. A conductive mesh pattern is formed upon the outer surface of the panel backplate in a manner so that each of the respective mesh openings surround a respective pin. A layer of semiconductor material is deposited over the mesh and the backplate exposed by the mesh openings, and a layer of insulation is deposited upon the layer of semiconductor. A charge pattern written on the layer of insulation acts to increase local conductivity in the semiconductor, causing increased current flow between local pins and adjacent mesh. Current flow through the pins determines a pattern of light emission corresponding to the charge pattern.

United States Patent [1 91' Kazan 1 Dec. 18, 1.973

[ IELD-EFFECT STORAGE TUBE WITH EAS-DISCHARGE OUTPUT [75] Inventor: Benjamin Kazan, Bedford Hills,

[73] Assignee: International Business Machines Corporation, Armonk, NY.

221 Filed: June 21, 1972 [21] Appl. No.: 265,018

[56] References Cited UNITED STATES PATENTS 8/1967 HeureuxL 313/89 9/1971 Barrekette 315/12 OTHER PUBLICATIONS Brighter Digital Readout Electronics, March 16, 1970, Weston & Hall, pp. 98-103 Primary Examiner-Leland A. Sebastian Assistant Examiner.1. M. Potenza Attorney-John A. Jordan et a].

s7 ABSTRACT A field-effect storage cathode ray tube is provided with a gas-discharge panel arrangement for display output. A transparent conductive mesh is mounted within the panel adjacent the transparent front plate thereof, and an array of conductive pins extend through the panel backplate from within the panel to the other surface of the backplate. A conductive mesh pattern is formed upon the outer surface of the panel backplate in a manner so that each of the respective mesh openings surround a respective pin. A layer of semiconductor material is deposited over the mesh and the backplate exposed by the mesh openings, and a layer of insulation is deposited upon the layer of semiconductor. A charge pattern written on the layer of insulation acts to increase local conductivity in the semiconductor, causing increased current flow between local pins and adjacent mesh. Current flow through the pins determines a pattern of light emission corresponding to the charge pattern.

15 Claims, 2 Drawing Figures FIELD-EFFECT STORAGE TUBE WITH EAS-DISCI-IARGE OUTPUT BACKGROUND OF THE INVENTION l. Field of the Invention The present invention relates to storage and display devicesQand more particularly to storage and display devices which utilize a field-effect storage tube with a gas-discharge output arrangement.

2. Description of the Prior Art Field-effect storage tubes are known in the prior art, as exemplfied by the teachings of Kazan and Winslow, in an article entitled Viewing Storage Tubes Based Upon Field-Effect Conductivity Control, appearing in the 1968 Proceedings of IEEE, Vol. 56, page l7l6l 717. Typically, such arrangements utilize a charge storage layer in contact with a semiconductor layer for controlling, at discrete points, the luminance of an electroluminescent phosphor. One of the difficulties encountered with such arrangements, however, re-

sides in the fact that the phosphor lifetime is short. Ac-

cordingly, in such typical arrangements the complete tube must be discarded upon expiration of the life of the phosphor. In addition to the short lifetime of the phosphor, such arrangements also suffer from low brightness.

In order to obviate, in general, the problems of short phosphor lifetime and the need for complete tube replacement, arrangements have also been employed in the prior art whereby a relatively long lifetime gas, housed in an array of separate chambers, is employed external to the cathode ray tube (CRT). In accordance with such' prior art arrangements, an electron beam is' employed to scan the inner surface of a CRT to ignite, via conductors, the gas at the discrete points in the separate chambers. Exemplary of such arrangements, is that described by D. M. Hart, in an article entitled Gas-Discharge Display Device, appearing in the IBM Technical Disclosure Bulletin, Vol. 12, No. 12, May

One of the difficulties with the piror art external gastype viewing storage tube arrangements, such as that typified by Hart, resides in the fact that since no charge storage layer is employed, (nor field-effect layer) the electron beam of the CRT must continuously scan the inner face to keep alive the gas ignition at the selected discrete points. Where efforts have been made in such arrangements to employ latching whereby gas ignition is maintained without the need for the continouus scan of the electron beam, the arrangements have been found to be somewhat ineffective and unsatisfactory. For example, in such latching arrangements, no gray scale is achievable. In addition, the voltages employed for latching must be completely removed, in order to turn off the supply tube. A

As a variation of the above-mentioned external gastype storage tube arrangements (utilizing a controllable electron beam), reference is also made to prior art arrangements that employ a photoconductive layer within a storage tube, having a compartmentilized gas panel external thereto. In such latter arrangements, discrete points in the gas panel, contiguous with the photoconductive layer, are selectively ignited in response to light impinging upon the layer, from a light source, or the like. However, such arrangements have, likefreshed, in the same manner as the above-mentioned Hart gas-type devices.

SUMMARY OF THE INVENTION In accordance with the principles of the present invention, an improved storage tube is obtained by utilizing charge storage and field-effect techniques, on the one hand, and gas panel display techniques, on the other. More particularly, in accordance with the principles of the present invention, an improved field-effect storage tube is obtained in a manner so as to provide a bright, readily replaceable and long-life display medium, in an arrangement which obviates the need for continuous scanning by the electron write beam, for purposes of refreshing the pattern displayed thereon.

To achieve this end, a viewing portion comprising two plates of glass, in sealed spaced-apart relationship act to form a panel to host a rare gas, such as neon. The inner surface of the outer glass plate is coated, for example, with a conducting mesh or thin conducting layer, which is relatively transparent. The inner glass plate is provided with an array of conducting pins or wires extending therethrough from the inner region with sealed gas to the outer surface thereof. The outer surface of the inner glass plate, on the electron beam side, is coated with a grid or mesh pattern of narrow conducting lines, which are deposited in the space between the conducting pins of the array of pins. Both the regions on the outer surface of this latter glass plate ex posed by the mesh or grid pattern openings and the conducting lines themselves, are coated with a film of semiconductor material which material, in turn, is coated with a thin film of insulator. By such an arrangement, a charge pattern is written upon the latter insulator, and the underlying semiconductor changes in conductivity thereat, in accordance with the density of the wise, been found ineffective and unsatisfactory. For example, such arrangements must continously be recharge in the pattern. Thus, the charges on the insulator control the local conductivity of the underlying semiconductor, thereby providing paths of varying resistance between the conducting lines forming the mesh pattern on the outer surface of the inner glass plate and the adjacent wires extending therethrough. In accordance with this local conductivity, the current flow through the gas from the end of a particular pin to the conducting mesh on the inner surface of the outer glass plate will be controlled, thus controlling the brightness of the local gas discharge therebetween in accordance with the charge pattern.

It is, therefore, an object of the present invention to provide an improved storage and display tube.

It is a further object of the present invention to provide an improved field-effect storage tube with both long life and a high level of brightness.

It is yet a further object of the present invention to provide a field-effect storage tube with gas-discharge output.

It is yet still a further object of the present invention to provide a field-effect storage tube which does not have to be continuously scanned in order to maintain the image to be stored.

It is another object of the present invention to provide a field-effect storage tube capable of gray scale operation.

It is yet another object of the present invention to provide an improved field-effect storage tube which exhibits long life, high brightness and does not require refresh operation to maintain the image, to be stored thereon.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings.

BRlEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a cross-section view of the field-effect storage tube, with gas-discharge output, in accordance with the principles of the present invention.

FlG. 1A is an enlargement of a portion of the layers of materials employed for the inner portion of the display surface, as shown in the vicinity of 1A, in the cross-sectional view of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. I, there is shown an embodied configuration of the field-effect storage and display tube, in accordance with the principles of the present invention. The overall configuration of the storage tube shown in FIG. 1 is, in general, analagous to any of the variety of cathode ray type storage and display tubes, employed in the prior art. Typically, envelope 3 of the storage tube is made of glass. The high energy electron writing gun shown at 5, comprises a conventional configuration whereby a charge pattern may be selectively written upon an appropriate surface. Specifically, it can be seen in the arrangement shown that high energy electron source 7 acts to emit high energy electrons through focusing element 9 and the field created by the vertical deflection plates 11 and 13. As is well known to those skilled in the art, the deflection plates 11 and 13 act to control the vertical position of the electron beam. For the sake of clarity, horizontal deflection plates have not been shown. However, as is likewise well known to those skilled in the art, the pair of horizontal deflection plates act to control the horizontal position of the electron beam.

As is clear from FIG. 1, the viewing portion 15 of the storage tube comprises two plates of glass 17 and 19 forming a chamber 20 filled with gas. Outer glass plate 17, it is clear, makes up the front viewing face of the storage and display tube. Glass plates 17 and 19 are spaced apart by spacer 21 and form a sealed region therebetween. Typically, the space between these glass plates may be of the order of several mm. The space between the glass plates may be filled with any ofa variety of rare gases, such as argon, and sealed. Likewise, neon, at a reduced pressure, would be effective for this purpose. However, it is clear that any of a variety of known gases capable of supporting glow discharge might be employed for this purpose.

The inner surface of outer glass plate 17 is coated, for example, with a thin conductive sheet or conductive mesh layer 23, which is relatively transparent.

In this regard, layer 23 as shown in FIG' 1 may be taken for purposes of description as a transparent conductive mesh. However, it is evident that layer 23 may as readily be a thin conducting transparent layer of tin oxide, for example.

Conductive mesh 23 is maintained at a positive potential by dc source 25. Typically, source 25 would act to hold the mesh at about I50 volts. It is clear, that mesh 23 may comprise any of a variety of metals or metal oxides which are preferably somewhat transparent. As shown in FIG. 1, the mesh is in contact with glass plate 17. Such an arrangement may be fabricated by conventional deposition and etching techniques, whereby tin oxide, for example, is deposited upon the glass, and the mesh pattern etched therein. However, instead of layer 23 being in contact with the glass, a conductive mesh supported freely, i.e., separated from glass plate l7,may be employed. Where mesh 23 is supported freely, glass plate 17 may be spaced further from inner glass plate 19.

As shown, inner glass plate 19 is provided with an array of conducting wires or pins 27 extending therethrough. These pins may be equally spaced apart in all directions. Typically, the pins might be located several mm., on center.

The surface of inner glass plate 19, on the electron beam side thereof, is first coated with a grid or mesh pattern of conducting narrow lines 29. These lines, as shown, may be vertically deposited in the space between the conducting pins 27 of the array of conducting pins. Thus, the conducting narrow lines may form a grid pattern which is positioned upon the inner surface of glass plate 19 so that the respective grid lines are between respective rows of conducting pins.

However, in the preferred mode, lines 29 would be arranged both horizontally and vertically, so as to form a conductive mesh pattern. Such a mesh pattern may be positioned so that the respective pins 27 are positioned at the approximate geometric center of the respective mesh openings. The mesh is maintained at ground potential, as shown, by ground connection wire 31. In this regard, it should be noted that wire 31 has been shown as extending up through the cross-section to connect each conducting line. However, it should be understood that this wire is shown merely to schematically represent the fact that all conducting lines are electrically connected to ground. In actual fact, such wire would not exist as shown. For example, if a conductive mesh were employed, it is clear that the wire would only run to some point on the periphery thereof.

Next, both the exposed surface of inner glass plate 19 and lines 29 of the conductive mesh are coated with a thin film of semiconductor material 33. The film of semiconductor material, then, is made to contact the inner surface of glass plate 19 at all points where there is no conducting mesh lines 29. This is shown, more clearly, in FIG. 1A. There it can be seen that semiconductor film 33 is deposited upon the ends of pins 27, the exposed surface of glass plate 19 and conducting mesh 29.

The outer surface of the film of semiconductor material 33 is then coated with a thin film of insulator 35. As is evident, the thin film of semiconductor material 33 may be deposited upon glass plate 19 by any of a variety of conventional deposition techniques. Likewise, the thin film of insulator 35 may be deposited upon the thin film of semiconductor 33 by the same or different deposition techniques. Alternatively, these latter thin tivcly coupled together. As shown in FIG. 1, the collector grid is connected to an input signal source 41. As is well known to those skilled in the art, signal source 41 acts to control or modulate the potential pattern established on surface 35Aof insulator 35 by the electron beam. Alternative to the arrangement shown, collector grid 39 may be held at a fixed potential, and the inten sity of the electron beam from electron writing gun S varied in accordance with the input signal.

in operation, insulator 35 is scanned by the unmodulatcd electron beam while the input signals are applied to collector grid 39. Thus, a charge pattern is created upon the inner surface 35A of insulator 35, in accordance with the signal provided by source 41. The charges on insulator 35, in turn, act to control the local conductivity of the semiconductor material therebelow, thus providing paths of varying resistance between conducting lines 29 on the surface of glass plate 19 and the most adjacent pin thereto, extending through the glass plate. Depending'upon the local resistance between a given pin and conducting line, the current flow through the gas in chamber 20 from the end of this pin to mesh 23 on the inner surface of outer glass plate 17 will be controlled, thereby controlling the brightness of the local gas discharge. Thus, as shown in FIG. 1, the magnitude of the density of the charge on surface A of insulator 35 acts to control the local resistance in semiconductor 33 between the involved pins 27 and conducting narrow lines 29. Where the density of the charge pattern on surface 35A adjacent a particular pin 27 and conducting line 29 is high, the local resistivity of the semiconductor is low and the current through the pin is high, thereby providing a relatively bright local gas discharge in chamber 20, in the vicinity of the particular pin.

it can be seen from the previous discussion, that the type of semiconductor employed is such that its conductivity increases with the charge density in question. However, it is clear that other types of semiconductors could be employed, whereby conductivity would de crease with increasing charge density.

Accordingly, it can be seen that with a complete charge pattern arrayed upon insulator 35, that the semiconductor therebeneath and the associated pins therefor, act to project the image of the charge pattern, in terms of current, into the gas in chamber 20. It is also clear, that gray scale is achieved due to the fact that the current flowing through the respective pins of the projected image varies in accordance with the density of the charge upon surface 35A. The gas in chamber 20, local to the respective pins, varies in the intensity of the glow discharge thereat, in accordance with the magnitude of the current flow through the respective pins. Thus, in accordance with the charge pattern stored on insulator 35, a pattern of light emission, of varying intensity, will be generated in the layer of gas in chamber 20.

To obtain long life without sputtering defects, the ends of pins 27 extending through glass plate 19 may be etched away, thus recessing the metal thereof and creating a hollow cathode arrangement akin to that described in the Mar. 16, 1970 issue of Electronics, in an article entitled Brighter Digital Read Out with New Dot-Matrix Tube, pp. 98-103. As suggested therein, such cathodes are capable of operating at a current density of ma/cm with a corresponding brightness of about 300 foot lamberts, using neon as the gas.

Under such conditions, negligible sputtering effects occur because of the hollow-cathode effect, even after thousands of hours of operation. Likewise, with the above stated current density, and employing 1 mil pins on 10 mil centers (1,000 elements across the diameter of a 10 inch tube), the average current through the gas discharge would be less than 400 microamperes per inch, since the area of the pins would be less than one/- hundredth the area of the glass plate. in accordance with such an arrangement, high writing speeds are achievable.

While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

l. A field-effect storage tube, comprising:

display means including chamber means in panel form filled with a glow discharge gas and having a front transparent display surface plate including a transparent conductive mesh and a back plate having an array of conductive pins extending therethrough from the inner region of said chamber to the outer surface of said back plate so that glow discharge may be locally effected in said gas between selected ones of said pins and said transparent mesh at said front plate;

an array of conducting lines in contact with the said outer surface of said back plate and arranged so as to form a grid pattern thereon with the respective grid lines of the array of lines arranged between respective rows of pins of said array of pins and being isolated therefrom;

potential means applied between said transparent conductive mesh and the said array of conducting lines;

a layer of semiconductor material in contact with the said array of conducting lines and the said outer surface of said back plate not contacted by said array of conducting lines and being sufficient in the absence of a charge associated therewith to provide a given path resistance between the pins of said array of pins and the respective adjacent grid lines therefor;

a layer of insulating material in contact with said layer of semiconductor material; and

electron write gun means for writing a charge pattern over selected regions on said layer of insulating material to cause the underlying semiconductor material to vary in conductivity thereat and cause the said resistance path between the associated underlying pins and adjacent grid lines therefor to vary and effect control of local glow discharge in said chamber means at said pins in accordance with said pattern.

2. The storage tube as set forth in claim 1 wherein said conductivity varies as a function of the density profile of said charge pattern so that said glow discharge varies in brightness in accordance therewith, whereby gray scale operation is obtained.

3. The storage tube as set forth in claim 2 wherein said conductivity increases with charge density.

4. The storage tube as set forth in claim 2 wherein said array of conducting lines comprise both vertical and horizontal lines in contact with the said outer surface so as to form a mesh pattern thereon with the: respective openings in the array of openings in said pattern surrounding respective pins in said array of pins.

5. The storage tube as set forth in claim 4 wherein collector grid means are positioned between said layer of insulating material and said electron write gun means and potential means applied thereto for controlling said pattern in accordance with variations in said potential.

6. The storage tube as set forth in claim 5 wherein said array of conducting lines is deposited upon the said outer surface of said back plate.

7. The storage tube as set forth in claim 5 wherein the pins of said array of conductive pins are recessed from the surface of said back plate on the inner region of said chamber.

8. The storage tube as set forth in claim 7 wherein said array of conducting lines are grounded and said transparent conductive mesh is biased to a positive potential with respect to ground.

9. The storage tube as set forth in claim 8 wherein said transparent conductive mesh is deposited upon said transparent display surface plate.

10. in a field-effect storage tube including electron write gun means and electron write surface means, said electron write surface means including a layer of insulator for writing a charge pattern thereon mounted in contact with a layer of semiconductor material so as to vary the conductivity of the semiconductor material in the regions therebelow in accordance with the charge pattern stored on said layer of insulator, the improvement, comprising:

display means including a first layer of transparent material forming front display surface and a second layer of material separated from said first layer of material and arranged to form a chamber therebetween for storing a glow-discharge type gas, said second layer having included therein an array of conductive pins each of which extends therethrough from within said chamber to the outside surface thereof and in contact with said layer of semiconductor material, and said first layer having mounted adjacent thereto means to effect glow discharge in said chamber adjacent said pins in response to sufficient current flow through said pins; horizontal and vertical array of relatively narrow conductors in contact with said layer of semicon-. ductor material and arranged between the said outside surface of said second layer and said layer of semiconductor material so as to form a mesh pattern thereon, with the mesh openings of said mesh pattern acting to surround at least one of the pins of said array of pins and be resistively connected thereto via the semiconductor material therebetween, said semiconductor material varying in resistance in accordance with the density of charge on the said layer of insulator in contact therewith; and

potential means coupled between said conductive lines and said means to effect glow discharge so that current will flow between said pins and the associated conductors of the mesh openings, respectively surrounding said pins, said current flowing in accordance with the density of the charge of said charge pattern on said layer of insulator in the region about said pins so as to thereby cause glow discharge in said chamber adjacent said pins in accordance with the magnitude of said current flow to thereby create a brightness pattern corresponding to said charge pattern.

11. The storage tube as set forth in claim 10 wherein said array of relatively narrow conductors are deposited upon the said outside surface of said second layer, said layer of semiconductor is deposited upon the said outside surface of said second layer and said narrow conductors and said layer of insulator is deposited upon said layer of semiconductor.

12. The storage tube as set forth in claim 1 1 wherein collector grid means are positioned between said layer of insulating material and said electron write gun means with said collector grid means having coupled thereto means for applying a potential thereto for controlling said pattern in accordance with variations in said potential.

13. The storage tube as set forth in claim 12 wherein the pins of said array of conductive pins are recessed from the surface of the inner chamber wall of said second layer.

14. The storage tube as set forth in claim 13 wherein said means to effect glow discharge in said chamber comprises a transparent conductive mesh mounted adjacent the inner surface of said first layer of material.

15. The storage tube as set forth in claim 14 wherein said array of narrow conductors are grounded and said transparent conductive mesh is biased to a negative potential with respect to ground.

UNITED STATES PATENT OFFICE fiETFKCATE 6F CECTIQN Patent No. 3,780 337 Dated December 18 1973 Inventor 5) n Kazan It is certified that error appears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

In the title, Change "EAS-DISCHARGE" t0 GAS-DISCHARGE-;

In the Abstract, line 7, change "other" to --outer--.

Signed and sealed this 23rd day of July 1974.

(SEAL) Attest:

MCCOY Ms GIBSON, JRQ c. MARSHALL DANN Attesting Officer Commissioner of Patents 4 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,780 337 Dated December 18 ,T 1973 Inventor 5) amln KaZ an It is certified that error appears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

.In the title, change "EAS-DISCHARGE" to --GASDISCHARGE-;

In the Abstract, line 7, change "other" to --outer-'-.

Signed and sealed this 23rd day of July 1971p.

(SEAL) Attest:

MCCOY M. GIBSON, JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. A field-effect storage tube, comprising: display means including chamber means in panel form filled with a glow discharge gas and having a front transparent display surface plate including a transparent conductive mesh and a back plate having an array of conductive pins extending therethrough from the inner region of said chamber to the outer surface of said back plate so that Glow discharge may be locally effected in said gas between selected ones of said pins and said transparent mesh at said front plate; an array of conducting lines in contact with the said outer surface of said back plate and arranged so as to form a grid pattern thereon with the respective grid lines of the array of lines arranged between respective rows of pins of said array of pins and being isolated therefrom; potential means applied between said transparent conductive mesh and the said array of conducting lines; a layer of semiconductor material in contact with the said array of conducting lines and the said outer surface of said back plate not contacted by said array of conducting lines and being sufficient in the absence of a charge associated therewith to provide a given path resistance between the pins of said array of pins and the respective adjacent grid lines therefor; a layer of insulating material in contact with said layer of semiconductor material; and electron write gun means for writing a charge pattern over selected regions on said layer of insulating material to cause the underlying semiconductor material to vary in conductivity thereat and cause the said resistance path between the associated underlying pins and adjacent grid lines therefor to vary and effect control of local glow discharge in said chamber means at said pins in accordance with said pattern.
 2. The storage tube as set forth in claim 1 wherein said conductivity varies as a function of the density profile of said charge pattern so that said glow discharge varies in brightness in accordance therewith, whereby gray scale operation is obtained.
 3. The storage tube as set forth in claim 2 wherein said conductivity increases with charge density.
 4. The storage tube as set forth in claim 2 wherein said array of conducting lines comprise both vertical and horizontal lines in contact with the said outer surface so as to form a mesh pattern thereon with the respective openings in the array of openings in said pattern surrounding respective pins in said array of pins.
 5. The storage tube as set forth in claim 4 wherein collector grid means are positioned between said layer of insulating material and said electron write gun means and potential means applied thereto for controlling said pattern in accordance with variations in said potential.
 6. The storage tube as set forth in claim 5 wherein said array of conducting lines is deposited upon the said outer surface of said back plate.
 7. The storage tube as set forth in claim 5 wherein the pins of said array of conductive pins are recessed from the surface of said back plate on the inner region of said chamber.
 8. The storage tube as set forth in claim 7 wherein said array of conducting lines are grounded and said transparent conductive mesh is biased to a positive potential with respect to ground.
 9. The storage tube as set forth in claim 8 wherein said transparent conductive mesh is deposited upon said transparent display surface plate.
 10. In a field-effect storage tube including electron write gun means and electron write surface means, said electron write surface means including a layer of insulator for writing a charge pattern thereon mounted in contact with a layer of semiconductor material so as to vary the conductivity of the semiconductor material in the regions therebelow in accordance with the charge pattern stored on said layer of insulator, the improvement, comprising: display means including a first layer of transparent material forming front display surface and a second layer of material separated from said first layer of material and arranged to form a chamber therebetween for storing a glow-discharge type gas, said second layer having included therein an array of conductive pins each of which extends therethrough from within said chamber to the outside surface thereof and in contact with said layer of semiconductor material, and said first layer having mounted adjacent thereto meanS to effect glow discharge in said chamber adjacent said pins in response to sufficient current flow through said pins; a horizontal and vertical array of relatively narrow conductors in contact with said layer of semiconductor material and arranged between the said outside surface of said second layer and said layer of semiconductor material so as to form a mesh pattern thereon, with the mesh openings of said mesh pattern acting to surround at least one of the pins of said array of pins and be resistively connected thereto via the semiconductor material therebetween, said semiconductor material varying in resistance in accordance with the density of charge on the said layer of insulator in contact therewith; and potential means coupled between said conductive lines and said means to effect glow discharge so that current will flow between said pins and the associated conductors of the mesh openings, respectively surrounding said pins, said current flowing in accordance with the density of the charge of said charge pattern on said layer of insulator in the region about said pins so as to thereby cause glow discharge in said chamber adjacent said pins in accordance with the magnitude of said current flow to thereby create a brightness pattern corresponding to said charge pattern.
 11. The storage tube as set forth in claim 10 wherein said array of relatively narrow conductors are deposited upon the said outside surface of said second layer, said layer of semiconductor is deposited upon the said outside surface of said second layer and said narrow conductors and said layer of insulator is deposited upon said layer of semiconductor.
 12. The storage tube as set forth in claim 11 wherein collector grid means are positioned between said layer of insulating material and said electron write gun means with said collector grid means having coupled thereto means for applying a potential thereto for controlling said pattern in accordance with variations in said potential.
 13. The storage tube as set forth in claim 12 wherein the pins of said array of conductive pins are recessed from the surface of the inner chamber wall of said second layer.
 14. The storage tube as set forth in claim 13 wherein said means to effect glow discharge in said chamber comprises a transparent conductive mesh mounted adjacent the inner surface of said first layer of material.
 15. The storage tube as set forth in claim 14 wherein said array of narrow conductors are grounded and said transparent conductive mesh is biased to a negative potential with respect to ground. 